THE GOVERNMENTS just-released Global 2000 Report to the President contains little that is new. But because of the overwhelming and almost unimaginable dimensions of the problems it portrays, it demands attention. The report pulls together for the first time all the various projections, economic models and analyses scattered around dozens of government agencies on the subjects of population growth, resources and environment. Its purpose was to put into a single document what the U.S. government now believes about how the world will look in the year 2000.

The report's findings are projections of current trends 20 years into the future -- not predictions. Such projections have their shortcomings. They do not take into account either prospective scientific discoveries that could change everything overnight or similarly transforming wars, political upheavals and natural disasters; they cannot predict consequential changes in government policy. But they do reveal where we are headed if things go on as they are.

Specifically, the report projects a world that is much more crowded than today's, more vulnerable to natural and political disruption, with fewer resources per person and vastly higher real costs of the necessities like food and energy. Though GNP is projected to increase by 145 percent in the last quarter of the century, the gains will be swamped by population growth in the developing countries, leaving a much wider gap between them and the industrialized nations.

Every major natural resource on which life depends -- forests, fisheries, fresh water, topsoil and arable land -- will be strained to or beyond its breaking point. Interestingly, the projections show that resource shortages will appear first among renewable resources, those that have come to be mistakenly thought of as inexhaustible. In energy, for example, the most serious projected shortfall is not for oil or any other type of finite fossil fuel. It is for firewood -- on which one-quarter of mankind depends for its energy. Genetic resources -- essential for maintaining the flexibility of plants and animals to respond to disease and climate change and for breeding higher-yield crops on which future food supply depends -- may be damaged most severely of all. At least 500,000 species -- perhaps 20 percent of the earth's total -- will be extinct in just 20 years.

Despite this forbidding picture, the report's projections clearly err on the side of optimism. In making each separate projection -- for food, for example -- the report assumes that the resources needed, such as land, energy, water, capital, will be available. This means that many resources have been allocated several times over. In some cases, evidence that these projections are unrealistic is already available.

The Global 2000's findings are largely consistent with those of many other recent studies, both domestic and international and, considering the many assumptions that have to be made, they are probably about as good as current knowledge can produce. Unfortunately, the phrase "year 2000" has a distant cosmic ring to it. Try to remember we are talking about the near future -- the day after tomorrow. That should make the urgency of trying to turn the report's grim warning into an international effort to alter that future self-evident.